The invention relates to a container closure for filling and emptying containers that can be inserted in an exchangeable manner into a container opening. The container closure consists of a plug head with a riser tube and a removal connection element that can be locked to the plug head by means of a stud coding system.
Container closures of this type are known. U.S. Pat. No. 4,699,298 describes a connecting device for inserting tubes or pipes into the plug opening of a drum for the purpose of delivering liquid from the drum. In order to avoid contamination of the liquids which are to be delivered from the drum, the connecting device has a mechanical stud coding system which has protrusions and recesses, with the result that a certain removal element can only be connected to the plug body when the corresponding protrusions and recesses match one another in accordance with the coding system. A coupling ring which engages on the outside is used for the screwed connection of the removal element, in which a respective part of the stud coding system is firmly integrated, i.e. forms a unit with the removal element. For different substances, which require different stud coding systems in order to avoid the unintentional combination of systems which have already been used for different liquids, the corresponding removal elements thus have to be of completely different configurations. This renders such container closures relatively expensive, since they have to be produced more or less individually.
Furthermore, U.S. Pat. No. 3,913,608 discloses a container connection element which has a bayonet closure in order for it to be possible to remove a connection element quickly and easily from a connection stub of a container and fit it thereon. There is no provision for any additional means for securing against unintentional connection of an element which has already been used for a liquid other than that in the container.
German Patent 103116 discloses a drum closure which makes it possible for a drum to be filled or emptied under pressure without the assembly being tapped. Provided in the plug of the drum closure described is a valve arrangement, which can be opened and closed by there being screwed on a discharge connection stub which matches the plug and has pipe sockets by means of which the valves are opened or, upon removal of the same, closed again. A stud coding system for securing the connection of a specific connection stub for a specific plug is not described.
Furthermore, U.S. Pat. No. 3,905,522 describes a liquid-discharge device for use with a connection cock or a connection element for liquid containers. This device has a plug head which bears an angled siphon tube, which extends into the interior of a drum which is to be emptied, and on which a removal element, which is connected to corresponding liquid lines, may be connected on the outside of a drum by means of screw threads. The device does not have a stud coding system. The siphon tube extends, at an angle with respect to the centre axis of the device, from the plug body into the drum, it being the case that the end of the adjoining siphon-tube piece, which is angled back again, is guided back as far as the imaginary centre axis of the device. The angling of the siphon tube is intended to prevent the tube which remains in the drum from colliding with the drum-filling equipment or disrupting the filling operation.
The object of the invention is thus to provide a container closure which, so as to prevent mix-ups, can only be connected to defined containers, which is cost-effective to produce, whose riser tube is protected against buckling upon insertion into the container and minimizes abrasion of the inside of the container, which ensures simultaneous liquid removal and ventilation, and which is better suited, in particular, for chemicals.
The container closure according to the invention serves for filling and emptying containers. It can be inserted into a container opening, which can receive a plug head, so as to be exchangeable. The container closure has a riser tube, which is connected to the plug head, and a removal connection element, it being the case that, when the plug head has been fitted in the container opening, the riser tube, which is connected to the plug head, extends into the container usually as far as the base of the latter. The removal connection element can be locked to the plug head by means of a stud coding system, in a position which is predetermined by the stud coding system, and is connected in a sealing manner to the plug head by means of a coupling stopper. In a manner known per se, the stud coding system has coding studs and matching coding recesses. According to the invention, the coding studs are provided on a first securing part and the coding recesses are provided on a second securing part, it being the case that one of the securing parts is designed as an annular disc, which can separately be fitted loosely onto the modular removal connection element such that it cannot readily be removed again therefrom, i.e. such that it cannot slip off, and the other of the securing parts is integrated in the plug head.
This inventive container closure for the removal of liquid chemicals from, in particular, drum-like transporting containers serves to avoid contamination by external influences which have an adverse effect on the purity of special liquid chemicals, e.g. high-purity chemicals for manufacturing electronic components. Such a removal system according to the invention ensures that the high degrees of purity of the special liquid chemicals mentioned remain intact even during removal operations. This is because, as a result of the special stud coding system, which according to the invention is provided as a separate component for the modular removal connection element, on the one hand, for reasons of safety and contamination, the risk of chemicals being mixed up is ruled out and, on the other hand, in terms of construction and dimensions, the actual removal connection element is identical for a vast range of different chemicals, the only difference being that the actual stud coding system has to be designed specifically for the respective application case. This makes it possible for such removal systems, which ensure the removal of specific chemicals with minimized contamination, nevertheless to be produced cost-effectively.
According to a preferred exemplary embodiment of the invention, the annular disc is designed as a studded disc, i.e. the coding studs are provided thereon such that they engage in coding recesses which are provided in the plug head and are distributed on the circumference of the latter in accordance with the arrangement of the studs. This means that the first securing part is designed in the form of the annular disc and the second securing part is integrated in the plug head. Of course, it is also possible for the annular disc to be designed as a perforated disc and for the plug head to have corresponding studs which, in a locking position, match the recesses in the annular disc. Such a stud coding system thus rules out any risk of mix-up upon connection to chemical supply systems.
According to a further preferred exemplary embodiment, the riser tube, which is connected to the plug head and extends into the interior of the container, is provided with a folding-bellows section. The plug head, which bears the riser tube, has an external thread by means of which it can be screwed into the drum-like transporting container, which likewise has a matching thread. The riser tube, which may also be referred to as a submerged tube, may preferably be fitted onto a cylindrical, tubular socket which extends into the interior of the container. In order, on the one hand, to ensure reliable, complete emptying of the liquid from the container, the riser tube has to extend as far as the base, i.e. the lowermost point of the container. When the plug head is screwed into the opening of the container, the folding bellows ensures that the distance between the container base and the screwed-in plug head is covered as required. The folding bellows avoids the situation where riser tubes rupture under the action of pressure upon insertion of the plug head into the opening of the container. Furthermore, the folding bellows is preferably of such a flexibility that friction of the riser tube on the container base or on the container wall is minimized to the extent where no particles are abraded from the surface of the container base or of the riser tube. Consequently, the fitting of the riser tube in conjunction with the plug head, does not result in any contamination of the special high-purity chemicals located in the container.
According to a further preferred exemplary embodiment, the riser tube has an opening funnel, which is oriented in the direction of the base of the container. Provided on the end side of said funnel are circumferentially spaced-apart webs which leave an inflow cross-section when the opening funnel has been positioned on the container base, with the result that the container can be emptied virtually completely without having to be tilted or upended. Moreover, the opening funnel ensures uniform extraction of the chemicals located in the container.
Provided beneath the opening thread in the container opening, in the case of the conventional containers, is a shoulder which serves the purpose, in conjunction with an O-ring seal which is arranged on the plug head beneath the external thread and rests against a mating shoulder, of reliable sealing on the exterior of the plug head. An inner section of the plug head is provided with an internal thread in which the coupling stopper, which has an external thread and engages through the annular disc, can engage such that the removal connection element and the plug head can be reliably connected to one another in a sealing manner. The coupling stopper is arranged in a loosely displaceable manner on a cylindrical section of the removal connection element, and the annular disc is arranged displaceably and loosely on a cylindrical section above the externally threaded section of the coupling stopper, said externally threaded section engaging through the annular disc.
According to a further preferred exemplary embodiment of the invention, the coding studs are designed as cylinder studs and circular-ring-segment studs, which are in a mirror-inverted and congruent arrangement with respect to the correspondingly formed coding recesses arranged on the circumference of the plug head. The circular-ring-segment studs preferably also serve as arresting aids.
On its side which is directed towards the plug head, the removal connection element preferably has a flange which bears a first O-ring for sealing the removal connection element with respect to the plug head. Said O-ring is arranged on the flange such that in the braced state, i.e. in the state in which the coupling stopper has been screwed in a fixed and sealing manner into the sunken internally threaded section of the plug head, the connection element is connected to the plug head in a sealing manner.
According to a further preferred exemplary embodiment of the invention, the removal connection element, which in addition to removing the chemicals from the container also serves to ventilate the latter, is provided with a cylindrical tube section which projects into a cylindrical plug-head part which bears the riser tube. This cylindrical tube section of the removal connection element has a smaller diameter than the cylindrical part of the plug head and projects deeper into the cylindrical part of the plug head, when the removal connection element has been fitted, than a ventilation opening arranged in said cylindrical part. Said cylindrical tube section also has a sealing ring which, when the removal connection element has been fitted, is located beneath the ventilation opening in the cylindrical part of the plug head and has such an external diameter that, when the removal connection element has been inserted into the plug head, said seal, which is preferably likewise designed as an O-ring, effects a reliable sealing action in the interior of the cylindrical part. Said second O-ring is preferably borne in a groove of the cylindrical tube section and, inter alia, for the purpose of improving the sealing action when the removal connection element has been fitted and secured by means of the coupling stopper, is seated on a reduced-diameter section in the interior of the cylindrical part of the plug head, which is bounded by an annular shoulder beneath the ventilation opening. The second O-ring rests in a sealing manner in said section.
This creates a venting channel from the ventilation opening into the removal connection element. In order to route ventilation outwards, by way of the removal connection element, to a ventilation opening, the cylindrical section is extended into the removal connection element and, between its outer surface and the inner surface of the removal connection element, forms a space which leads into the ventilation connection line provided on said removal connection element. The container closure according to the present invention thus permits simultaneous liquid removal and ventilation.
According to yet another preferred exemplary embodiment, the plug head also has a threaded section which differs from the sunken internally threaded section for the coupling stopper and into which a threaded stopper can be screwed for the purpose of sealing the open plug head when the removal connection element has been removed. However, it is also possible, for the purpose of reliably closing off the plug head in a sealing manner, for the threaded stopper to be fitted into the sunken internally threaded section provided for the coupling stopper.
The container closure is preferably produced from inert plastic, i.e. a plastic which is not attacked by the chemicals with which the container closure comes into contact.
Other objectives, features and advantages of the present invention will become apparent from the following detailed description. The detailed description, while indicating specific embodiments of the invention, are provided by way of illustration only. Accordingly, the present invention also includes those various changes and modifications within the spirit and scope of the invention that may become apparent to those skilled in the art from this detailed description.
Further advantages, features and possible applications of the invention will now be explained in more detail with reference to an exemplary embodiment in conjunction with the attached drawings, in which: